So I've created a heat map of call data but when changing the call status filter I get blank cells appearing rather than everything coloured in. This is presumably due to no data for that time of day so can I simply have the heat map colour in that blank cell using the lowest colour on the legend? For example blue = lowest and green = highest?

Hi Tushar, please find attached a sample workbook with only a small snapshot of my data. As you can see I don't have the full number of daily hours in this sample but you can get an idea of what I mean about the blank cells (white) where there are no records for certain hours and days. I would like these white cells to show as the minimum colour scale (dark red) if possible.

Hi Amit, I tried that and it looks like it worked as you can see the selected cell below has a volume of zero next to it BUT for some reason I have 3 blank (white) rows for the times 5AM, 10PM and 11PM.

I created a table of volumes to check this and there are no records for those times on each day but not sure why those rows are showing up as white, despite using your suggested calculation above - very frustrating.

We had to solve a similar problem recently...it was actually a colleague of mine who came up with this simple method! So plaudits to Joanna Pakes (...I accept the "correct answer" points on her behalf )